Geotechnical study in Zaragoza

In Zaragoza, soils of gypsum, anhydrite and salts predominate, accompanied in frequency by fine sands and silts. These materials exhibit notable permeability due to the presence of extensive aquifers, which favours a variable bearing capacity depending on their compaction. The presence of gypsum, anhydrite and salts introduces a risk of dissolution processes that may affect the stability of foundations, whereas sandy and conglomeratic materials generally offer greater structural assurances for shallow or semi-deep supports.

The seismicity in Zaragoza is notable, with 68 events in the last 30 years and a maximum magnitude (Mmax) of 4.8, which requires incorporating specific seismic criteria into any structural design. This is further compounded by the presence of karst phenomena associated with carbonate and evaporitic materials, which require thorough verification before executing the foundations in order to avoid unexpected subsidence or collapses. Since the substrate is not clayey, there are no risks associated with expansive soils. The main geotechnical constraint in Zaragoza is the interaction between karst processes and the dissolution of gypsum, both of which are critical aspects in defining the type and depth of foundation.